F135 Exceeds Expectations During Live Fire Survivability Testing

Pratt & Whitney, a division of United Technologies Corporation (NYSE: UTX), recently participated in a series of Live Fire Tests (LFT) in conjunction with the Naval Air Systems Command's (NAVAIR) Weapons Survivability Laboratory (WSL) to assess the F135 propulsion system's performance against ballistic damage.

The F-35 LFT included a series of tests designed to better understand the capabilities and vulnerabilities of the F135 upon sustaining ballistic damage. According to a recap of the trial, published by the Navy's Joint Aircraft Survivability Program Office (JASPO), "the test results were favorable, and in many cases, the propulsion system performed better than predicted."

Three F135 test series were conducted, including Short Takeoff and Vertical Landing (STOVL) propulsion system tests; dynamic and static engine ballistic tests; and finally, total fuel ingestion tests. These tests were aimed at better understanding the advanced engine control system, the capabilities of the main engine with battle damage, and to assess the engine's fuel ingestion tolerance.

According to the JASPO report, the "STOVL propulsion system was very tolerant of damage with little performance loss over the course of the testing." The report also indicated that the "propulsion control system is very capable in its ability to withstand and accommodate damage via built in redundancies… [and] the engine showed a high tolerance of ingested fuel."

The JASPO report concluded that damage to blades and vanes in both the lift fan and main engine did not result in catastrophic damage, and that, in fact, the F135 engine and its control system are capable of withstanding and accommodating damage, and providing information to alert the pilot to the damage sustained by the system. The data collected from these LFTs will be used to update assumptions used in the F135 vulnerability assessment.

"This series of tests on the CTOL/CV and STOVL variants is intended to mimic battlefield damage in wartime scenarios. The F135 is an amazing propulsion system that has proved its durability through this very rigorous testing by sustaining increasing levels of damage, yet continues to operate to the customer specifications," said Cheryl Lobo, director, F135 programs. "These tests should provide confidence in the capabilities of the propulsion system for our operators."

All testing was conducted at the Weapon Survivability Laboratory (WSL) in China Lake, California. In addition to Pratt & Whitney personnel, testing was conducted by personnel from the WSL; UTC Aerospace Systems; Lockheed Martin; Director, Operational Test and Evaluation (DOT&E); and the Institute for Defense Analysis.